Embodiments of the current invention are related to a prefabricated modular frame for use in a free-standing and/or lean-to structure, built as a timber framing system, and more particularly to a method and system of framework of load-bearing beams and posts made of prefabricated glued laminated modular timber frame members.
Timber framing and post-and-beam construction is a general term for building with heavy timbers—as opposed to “dimension lumber” such as 2-by-4's. Traditional timber frameworking has been used for erecting structures incorporating heavy, squared-off, and carefully-fitted and joined timbers with secured joints. Forming the framework elements demanded on-site skilled labor.
Modern timber structures often incorporate metal joinery such as gusset plates and bolts. Reference is currently made to FIG. 1, which is a schematic moment diagram showing a moment distribution 5 along a prior art beam 6, supported by prior art posts 7, which are in turn supported on two foundations, indicated as inverted triangles, as known in the art. In the moment diagram, an ordinate 8 represents moment (i.e. units of N-m, or lbf-ft) due to a force (indicated in the figure by an arrow) applied to beam 6, with zero, positive, and negative moment values indicated—all as known in the art.
In prior art methods of constructing post-and-beam structures—the posts and/or beams also referred to as “studs”—joints between posts and beams are designed to have essentially zero moments, as shown schematically in FIG. 1. Such current/prior art methods take into account a “zero moment assumption” to ensure mechanical stability and integrity of plates/bolts, which could otherwise be damaged and/or ripped away at a joint having a moment substantially not equal to zero.
A stud functions to support and/or be integrated into a load-bearing wall. Studs, when incorporated in such a wall, essentially act as a stable frame to which interior and exterior wall coverings, generally not designed to support building loads themselves—and also referred to as “curtain walls”—are attached thereupon. Studs are typically expensive elements, traditionally comprising high quality and expensive wood, and are suitable to bear heavy loads. Used as posts and beams, studs serve as vertical and horizontal members of exterior walls and of interior partitions, such as wall plates and lintels. Studs additionally serve as a nailing base for covering material, inter alia.
Other wood construction has employed a variety of framing methods, also known in the art as “light-frame construction” and “framework construction” methods.
Studs are typically supported on a bottom plate or a foundation sill, herein referred to simply as “foundation”. Studs serve to support a top plate, as known in the art. In tall framework construction buildings, studs which comprise a frame are usually augmented by additional posts, especially at corners and/or mid-points of extended walls. Some prior art framework construction methods use light prefabricated elements, which typically serve as walls and ceiling elements and which are integrated into the building at a construction site. A prior art example of an element of a frame-type structure is that of Steinberg (the inventor of the current application) in U.S. Pat. No. 8,561,374, whose disclosure is incorporated by reference.
In most current/prior art buildings utilizing lumber framework, during construction (and sometimes even after building construction) studs and/or frames serving as walls must be additionally supported by diagonal supports to ensure stability, at least during construction. In other words, framework construction walls, as described hereinabove are typically not intrinsically free-standing.
In the specification and claims which follow, the term “free-standing”, when used in conjunction with frame construction, is intended to mean studs and/or frames which serve as walls that do not need additional support to ensure stability during construction, as described hereinabove. An integratable framework, which is prefabricated and which could be constructed in a free-standing mode, could greatly reduce on-site labor, requiring only semi-skilled labor, and would reduce labor and material costs and subsequently generally reduce overall building cost.
In the specification and claims which follow, the terms “glulam” and “glued laminated timber” are intended to mean a type of structural timber element known in the art, composed of several layers of dimensional lumber bonded together with durable, moisture-resistant adhesives. A single large elongated glulam structural member is typically fabricated by laminating several layers of lumber, thereby optimizing the structural value of the member. Laminated structural members are used as vertical columns or horizontal beams—i.e. studs. Glulam beams are frequently used in the construction industry in place of conventional wood timber to serve as elements such as: beams; columns; cantilevered supports; and/or trusses to provide structural support and integrity. Glulam beams are structurally more sound and are often less expensive than conventional wood products. Glulam beams and posts could be therefore incorporated in a frame structure described hereinabove to afford additional material cost and construction cost advantages.
There is therefore a need for a system and method of constructing a employing free-standing prefabricated glued laminated modular timber frame members to effectively address the problems and provide benefits described hereinabove.